scholarly journals Mechanochemical synthesis and consolidation of nanostructured cerium hexaboride

2019 ◽  
Vol 13 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Duygu Ağaoğulları ◽  
Özge Balcı ◽  
Nazlı Akçamlı ◽  
Challapalli Suryanarayana ◽  
İsmail Duman ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Resistivity ◽  
Mechanochemical Synthesis ◽  
High Purity ◽  
Average Particle Size ◽  
High Energy ◽  
Wear Behaviour ◽  
Size Analysis ◽  
Average Particle ◽  
Scanning Calorimetry

This study reports on the mechanochemical synthesis (MCS) and consolidation of nanostructured CeB6 powders of high purity. CeB6 powders were prepared via MCS by milling CeO2, B2O3 and Mg powders in a high-energy ball mill for different milling times. The effects of milling time on the formation, microstructure and thermal behaviour of the synthesized powders were investigated and the optimum MCS duration was determined. Purified powders were obtained after HCl leaching by removing MgO by-product. The prepared powders were characterized by a number of techniques including X-ray diffraction, stereomicroscopy, scanning and transmission electron microscopy coupled with energy dispersive spectrometry, differential scanning calorimetry, atomic absorption spectrometry, particle size analysis, surface area analysis and vibrating sample magnetometry. The high-purity CeB6 powders having an average particle size of 86 nm were consolidated by cold-pressing followed by pressureless sintering at 1700 ?C for 5 h. The bulk CeB6 specimen was investigated for its microstructure, density, electrical resistivity, surface roughness and some mechanical properties (microhardness and wear behaviour). The relative density, electrical resistivity, microhardness and wear rate of the bulk CeB6 were determined as 95.2%TD, 57.50 ?W?cm, 11.65GPa and 1.46 ? 10?4 mm3/N?m, respectively.

Synthesis and Characterization of Polyimide/Silica Nanocomposites

2011 ◽  
Vol 311-313 ◽  
pp. 96-100
Author(s):  
Jian Li Cheng ◽  
Cun Zhou ◽  
Hao Peng ◽  
Huan Wang ◽  
Yu Sun
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Amic Acid ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Size Of Particles

Two kind of polyimide/silica nanocomposites which were recorded poly(amic acid)/ silica(PAA/SiO2) and SiO2in poly(amic acid) ammonium salt(PAS/SiO2) respectively, have been prepared for different methods. The size of SiO2in PAA/SiO2and PAS/SiO2are measured by Particle size analysis and the average particle size are 377nm and 53.7nm. Transmission electron microscopy(TEM) images of PAS/ SiO2confirm that the size of particles are ranged from 40 to 80nm. The stuctures of samples have been characterized by FT-IR spectra. The thermal stability of PAA/SiO2and PAS/SiO2are studied by thermogravimetric analysis (TGA) and the thermal behaviors were investigated by differential scanning calorimetry (DSC) in this paper. It is shown that PAA/SiO2have slightly better thermal properties than that of PAS/SiO2. The results obtained from Instron universal strength tester present the water-solube PAS/SiO2own the excellent mechanical prperties as same as PAA/SiO2.

Synthesis of Emulsion for Water-Based Pigment Ink Jet

2011 ◽  
Vol 380 ◽  
pp. 81-84
Author(s):  
Li Ming Zhang ◽  
Xiu Lan Xin ◽  
Wei Jiang
Keyword(s):  
Particle Size ◽  
Water Resistance ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Reactive Surfactant ◽  
Potential Value ◽  
Ink Jet ◽  
Water Based ◽  
Pigment Ink

The water-based pigment ink jet emulsion whose particle size was less than 100nm was synthesized by the polymerization of methyl methacrylate, butyl acrylate and ethylhexyl acrylate, and anionic reactive surfactant and nonionic surfactant were used as the emulsifiers. The effects of particle size and water resistance were studied. The glass transition temperature was tested by differential scanning calorimetry. The average particle size of emulsion was range from 60nm to70nm, zeta potential value was less than -60mv; viscosity was 3.5mps; water absorption was 5.9%.

Dual synthesis of Silver and Iron oxide nanoparticles from edible greens Amaranthus Viridis and their in vitro antioxidant activity and antimicrobial studies

2021 ◽  
Vol 10 ◽  
Author(s):  
Venkata Subbaiah Kotakadi ◽  
Bhulakshmi Kolapalli ◽  
Susmila Aparna Gaddam ◽  
Sai Gopal Divi Venkata Ramana
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
Iron Nanoparticles ◽  
Average Particle Size ◽  
Leafy Vegetable ◽  
Size Analysis ◽  
Average Particle

Background: There is an increasing commercial demand for nanoparticles due to their wide applicability in various areas such as chemistry, catalysis, energy and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques where the chemicals used are quite often toxic and flammable. Objective: In the present study, we described a simple, cost effective and environmentally-friendly technique for green synthesis of silver and iron nanoparticles by using the aqueous extract of leafy vegetable Amaranthus viridis as a reducing agent. Methods: The silver and Iron nanoparticles (Av-AgNPs, Av-IONPs) were characterized by different spectral methods. The surface Plasmon resonance spectrums of Av-AgNPs, Av-IONPs were recorded at 422nm and 261nm. The Scanning electron microscopy (SEM) analysis reveals that the Av-AgNPs, Av-IONPs are roughly spherical in shape. Energy dispersive absorption spectroscopy (EDAX) of biosynthesized Av-AgNPs, Av-IONPs indicates the reduction of silver ions to elemental silver and iron ions to elemental iron. Results: The particle size analysis of Av-AgNPs and Av-IONPs was carried out by Dynamic light scattering (DLS) method the results reveal that both Av-AgNPs and Av-IONPs were polydispered in nature. The average particle size of Av-AgNPs is 55.8 nm with a polydispered index (PI) of 0.297, similarly the average particle size of Av-IONPs is 80.6 nm with an polydispered index (PI) of 0.469. Zeta-potential of Av-AgNPs was detected at -24.6 mV and Av-IONPs were detected at 28.8 mV, the result reveals that they high stability due their high negative charge and positive charge respectively. The dual synthesized Av-AgNPs, Av-IONPs exhibits excellent antioxidant activity by DPPH, H2O2 and NO methods. DPPH was proven to be the best when compared with the other two methods. The biosynthesized Av-AgNPs, Av-IONPs proved to have very good antimicrobial activity against gram +ve and gram –ve bacteria. Conclusion: when compared with standard antibiotic. There were several reports on green synthesis of metal nanoparticles using various plant parts, but here edible leafy vegetable Amaranthus viridis was used for biosynthesis of both Av-AgNPs and Av-IONPs.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

Melting Behavior in Granular Metal Thin Films

1990 ◽  
Vol 195 ◽  
Author(s):  
Karl M. Unruh ◽  
B.M. Patterson ◽  
S.I. Shah
Keyword(s):  
Particle Size ◽  
Melting Temperature ◽  
Average Particle Size ◽  
Melting Behavior ◽  
Multilayer Films ◽  
Relative Reduction ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Metal Thin Films ◽  
Solid Liquid

ABSTRACTGranular metal films consisting of small Sn, Bi, and Pb particles, typically from less than 100 Å to several 1000 Å in size and embedded in a SiO2 matrix, have been fabricated over a range of metal compositions by RF sputter deposition. Two different film geometries have been prepared, homogeneous films and multilayer films consisting of alternating layers of granular metal and SiO2. These films have been characterized by x-ray diffraction and transmission electron microscopy and their melting behavior studied by differential scanning calorimetry. As the concentration of the metal component is decreased, the average particle size decreases and the particle size distribution becomes more narrow. When the solid-liquid transition is studied, the melting temperature has been found to be increasingly depressed as the particle size is reduced. In the smallest particles the relative reduction in the melting temperature is greater than 10 percent. No strong evidence for melting point enhancements, due to pressureeffects arising from the different thermal expansions of the metal particles and the SiO2 matrix, has been observed in either the homogeneous or multilayer films.

scholarly journals Physicochemical, Digestive, and Sensory Properties of Panax Notoginseng Saponins Encapsulated by Polymerized Whey Protein

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2942
Author(s):  
Zengjia Zhou ◽  
Xiaomeng Sun ◽  
Jianjun Cheng ◽  
Qingfeng Ban ◽  
Mingruo Guo
Keyword(s):  
Particle Size ◽  
Whey Protein ◽  
Functional Foods ◽  
Average Particle Size ◽  
Panax Notoginseng ◽  
Intermolecular Forces ◽  
Sensory Properties ◽  
Average Particle ◽  
Panax Notoginseng Saponins ◽  
Scanning Calorimetry

Panax Notoginseng Saponins (PNS) may be beneficial to human health due to their bioactive function. The application of PNS in functional foods was limited due to the bitter taste and low oral bioavailability. PNS were encapsulated by polymerized whey protein (PWP) nanoparticles. The physicochemical, digestive, and sensory properties of the nanoparticles were investigated. Results showed that the nanoparticles had a particle size of 55 nm, the zeta potential of −28 mV, and high PNS encapsulation efficiency (92.94%) when the mass ratio of PNS to PWP was 1:30. Differential Scanning Calorimetry (DSC) results revealed that PNS were successfully encapsulated by PWP. The mainly intermolecular forces between PNS and PWP were hydrogen bonding and electrostatic attraction confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Results of simulated gastrointestinal digestion indicated that the PNS-PWP (1:30) nanoparticles had smaller average particle size (36 nm) after treatment with gastric fluids and increased particle size (75 nm) after treatment with intestinal fluids. Transmission Electron Microscopy (TEM) micrographs reflected that the nanoparticles had irregular spherical structures. The encapsulated PNS exhibited significantly (p < 0.05) decreased bitterness compared to the non-encapsulated PNS confirmed by the electronic tongue. The results indicated that encapsulation of PNS with PWP could facilitate their application in functional foods.

scholarly journals INVESTIGATION ON DISSOLUTION PATTERN AND MATHEMATICAL MODELING OF DRUG RELEASE OF QUERCETIN BY COMPLEXATION WITH CYCLODEXTRIN NANOSPONGES

2019 ◽  
pp. 260-264
Author(s):  
SOBITHARANI P ◽  
ANANDAM S ◽  
MOHAN VARMA M ◽  
VIJAYA RATNA J ◽  
SHAILAJA P
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Water Soluble ◽  
Size Analysis ◽  
Average Particle ◽  
Scattering Method ◽  
Release Pattern ◽  
Cyclodextrin Nanosponges

Objective: The main objective of this study was to investigate the release pattern of a poorly water-soluble drug quercetin (QU) by fabricating its cyclodextrin nanosponges. Methods: Characterization of the original QU powder and QU-loaded nanosponges was carried out by the Fourier-transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and dissolution tester. The drug release pattern was subjected to various kinetic models. Results: FTIR studies confirmed the formation of inclusion complex of drug. The particle size analysis revealed that the average particle size measured by laser light scattering method is around 400–420 nm with low polydispersity index. The particle size distribution is unimodal and having a narrow range. A sufficiently high zeta potential indicates that the complexes would be stable and the tendency to agglomerate would be miniscule. TEM image revealed the porous nature of nanosponges. The dissolution of the QU nanosponges was significantly higher compared with the pure drug. Conclusion: From the kinetic study, it is apparent that the regression coefficient value closer to unity in case of Korsmeyer-Peppas model indicates that the drug release exponentially to the elapsed time. n value obtained from the Korsmeyer-Peppas plots, i.e., 0.9911 indicating non-Fickian (anomalous) transport ; thus, it projected that delivered its active ingredient by coupled diffusion and erosion.

scholarly journals The influence of powder particle size on properties of Cu-Al2O3 composites

2009 ◽  
Vol 41 (2) ◽  
pp. 185-192 ◽  
Author(s):  
V. Rajkovic ◽  
D. Bozic ◽  
M. Popovic ◽  
M.T. Jovanovic
Keyword(s):  
Thermal Stability ◽  
Particle Size ◽  
Grain Size ◽  
Copper Powder ◽  
Average Particle Size ◽  
High Energy ◽  
Average Particle ◽  
Size Refinement ◽  
Al2o3 Particles ◽  
Milled Powders

Inert gas atomized prealloyed copper powder containing 2 wt.% Al (average particle size ? 30 ?m) and a mixture consisting of copper (average particle sizes ? 15 ?m and 30 ?m) and 4 wt.% of commercial Al2O3 powder particles (average particle size ? 0.75 ?m) were milled separately in a high-energy planetary ball mill up to 20 h in air. Milling was performed in order to strengthen the copper matrix by grain size refinement and Al2O3 particles. Milling in air of prealloyed copper powder promoted formation of finely dispersed nano-sized Al2O3 particles by internal oxidation. On the other side, composite powders with commercial micro-sized Al2O3 particles were obtained by mechanical alloying. Following milling, powders were treated in hydrogen at 400 0C for 1h in order to eliminate copper oxides formed on their surface during milling. Hot-pressing (800 0C for 3 h in argon at pressure of 35 MPa) was used for compaction of milled powders. Hot-pressed composite compacts processed from 5 and 20 h milled powders were additionally subjected to high temperature exposure (800?C for 1 and 5h in argon) in order to examine their thermal stability. The results were discussed in terms of the effects of different size of starting powders, the grain size refinement and different size of Al2O3 particles on strengthening, thermal stability and electrical conductivity of copper-based composites.

Formulation and Characterization of Nateglinide Nanosuspension by Precipitation Method

2014 ◽  
Vol 7 (4) ◽  
pp. 2685-2691
Author(s):  
Amruta Papdiwal ◽  
Kishor Sagar ◽  
Vishal Pande
Keyword(s):  
Particle Size ◽  
Dissolution Rate ◽  
Water Solubility ◽  
Average Particle Size ◽  
Biologically Active ◽  
In Vitro Dissolution ◽  
Precipitation Method ◽  
Average Particle ◽  
Scanning Calorimetry

Poor water solubility and slow dissolution rate are major issues for the majority of upcoming and existing biologically active pharmaceutical compounds. Nateglinide is Biopharmaceutical Classification System Class-II drug that has low solubility and high permeability. The purpose of the present study was to improve the solubility and dissolution rate of Nateglinide by the preparation of nanosuspension by the nanoprecipitation technique. Nateglinide nanosuspension was evaluated for its particle size, in vitro dissolution study, and characterized by differential scanning calorimetry and scanning electron microscopy. The optimized formulation showed an average particle size of 207 nm and zeta potential of -25.8 mV. The rate of dissolution of the optimized nanosuspension was enhanced by 83% in 50 min relative to micronized suspension of nateglinide (37% in 50 min). This improvement was mainly due to the formulation of nanosized particles of Nateglinide. Stability study revealed that nanosuspension was more stable at room temperature and refrigerator condition with no significant change in particle size distribution. These results indicate that the nateglinide loaded nanosuspension may significantly improve in vitro dissolution rate and thereby possibly enhance the onset of therapeutic effect.

Influence of Fineness on Activity Index of Blast Furnace Slag with Different SiO2/Al2O3

2015 ◽  
Vol 814 ◽  
pp. 579-582
Author(s):  
Su Ping Cui ◽  
Ling Ling Liu ◽  
Ya Li Wang ◽  
Hui Wang ◽  
Shi Jie Dong
Keyword(s):  
Particle Size ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Activity Index ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Furnace Slag ◽  
Activity Indices

Granulated blast furnace slag (GBFS) is a by-product of ironmaking and widely used in the cement and concrete. GBFS samples with different ratio of SiO2/Al2O3 were prepared under the laboratory conditions and ground by the agate ball mill at different times. Then they were characterized by laser particle size analysis (LPSA), scanning electron microscopy (SEM), Bertrand surface method and mechanical testing. It was found that the activity index of GBFS clearly increased with the decrease of the GBFS particle size. In the case of the average particle size about 32μm, the activity indices were irregular with the increase of SiO2/Al2O3 ratio, whereas for the average particle size about 11μm, the activity indices decreased with the increase of SiO2/Al2O3 ratio.

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